1. Field of the Invention
The present invention relates in general to a material handling system and, more particularly, to a mechanically actuated plate clamp.
2. Description of the Prior Art
When recycling large transformers, especially transformers of one megavolt-ampere (MVA) or greater, it is desirable to preserve the metallic laminations from the transformer's core. Due to the unique construction of the laminations, it is desirable to remove the laminations and place them on a transport vehicle with a minimum of damage3 so that the laminations can be reused or cut as desired to use in smaller transformer applications.
Prior art material handling machines can be used to move laminations. Drawbacks associated with using prior art material handling machines to move laminations include damage to the laminations from gripping too tightly or damage from dropping laminations gripped too loosely. It would, therefore, be desirable to provide a system for removing and handling laminations without damaging them.
It is known in the art to provide a plate clamp for the movement of large flat pieces of material. Prior art plate clamps include two parallel plates divided by a spacer and forming a mouth. A curved tooth is journaled between the plates for movement within the mouth. When a large plate is positioned in the mouth, the tooth moves into contact with the plate. As the plate clamp is moved away from the plate, such as when attempting to lift the plate, the movement of the plate out of the mouth of the plate clamp causes the tooth to pivot into further engagement with the plate.
The curved tooth, therefore, pins the plate between the lower law of the parallel plates and the tooth. Additional movement of the plate in a direction out of the mouth further pinches the plate between the tooth and the lower jaw. In the prior art, the plate clamp is coupled to ropes or cables and lifted upward to move a plate to a desired location. When it is desired to release the plate clamp, the plate clamp is moved toward the plate to move the plate further into the mouth of the plate clamp. As the plate moves further into the mouth of the plate clamp, the pinching pressure between the tooth and lower jaw is released, thereby allowing the tooth to pivot inward, upward and away from the plate. The plate may thereafter be released from the plate clamp.
One drawback associated with the prior art plate clamps is that prior art plate clamps are typically moved with ropes or cables within a warehouse or other interior setting. The use of ropes or cables makes it difficult to utilize prior art plate camps outdoors, and to accurately control the movement of the plate clamp. Additionally, the use of ropes or cables in association with the plate clamp does not allow for pivoting of the plate clamp to allow the plate clamp to angle the plate upward as it is being moved.
An additional drawback associated with prior art plate clamps is that prior art plate clamps cannot be moved toward the plate without risking a loss of pressure on the plate and disengagement of the plate from the plate clamp. Similarly, the prior art plate clamp cannot be inverted, as gravity would force the plate into the mouth of the plate clamp, thereby releasing the pressure on the plate and allowing the plate to dislodge from the mouth of the plate clamp.
Still another problem associated with prior art plate clamps is the shallowness of the mouth associated with such clamps. It would be desirable to provide a plate clamp with a deeper mouth, allowing for securement of a wider range of materials within the mouth of the plate clamp. Yet another drawback associated with the prior art is the inability to easily disengage the plate clamp from a plate while the plate is raised. It would, therefore, be desirable to provide a material handling system which could be remotely actuated to secure a plate or other large piece of material and to move that piece of material to another position before release. It would also be desirable to provide such a material handling system with a deep mouth and secure mechanical engagement of a plate between a tooth and a lower jaw. It would be desirable to provide such a device the ability to secure the material even when the material handling system is moved toward the material, or the material is being forced by gravity deeper into the mouth of the material handling system.
It would be desirable to provide a material handling system which could be released from the material even when the material is being suspended downward and gravity is acting on the material in a direction outward from the mouth of the material handling system. It would also be desirable to provide such a material handling system on a vehicle mounted boom or other system for utilizing the material handling system outdoors and to position the material handling system at a plurality of heights and orientations as desired to move material.
In material handling situations, such as removing laminations from used electric transformers, prior art plate clamps are not maneuverable enough or precise enough to accurately and safely remove the sharp laminations from a transformer. Accordingly, this process must be accomplished by hand, exposing workers to dangerously sharp metal edges. It would, therefore, be desirable to provide a material handing system which could remotely handle hazardous materials, such as sharp edged metal plates, remotely with a smaller number of workers. The difficulties encountered in the prior art discussed hereinabove are substantially eliminated by the present invention, proving a safer material handling system utilizing a fewer number of workers.